Jim, Sebastien

We did a high resolution measurement on HAM3-ISI (bandwidth of 1mHz), with and without the sensor correction. At this point, we can say that:

- the feautre appears only when the sensor correction is ON

- it appears on all DOFs except RZ

- it's a very high Q 0.66Hz feature. This last point convinces us that it must be an electronic issue somehow.

I attached the plots and committed the DTT sessions of those measurements in the svn:

/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/HAM3/Misc/HAM3_debug

/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/HAM3/Misc/HAM3_debug-with_SC

We also checked that this feature was not due to a beating between the HEPI IPSs. We turned the position loops of HEPI HAM3 off. We even powered off the pier electronic boxes we no change: the peak is still here when the sensor correction is ON.

The investigation continues...

The door is going back on at BSC9 after having the door off for ~45 minutes.

The temperature at ENDX has been set to 68F. Hopefully we can keep it there. This is now the same as ENDY.

The plot shows 2 days of trend.

Evan, Alexa, Thomas

We repeated the Y arm loss measurement that we did yesterday in alog 15919. We followed the same steps and found: green TR buildup was 1.018, IR TR buildup was 11.2(0.5), Poff = 1303(5), and Pon = 1251(5). This gives a loss of 155(19)ppm, which is still suffeciently low, and within uncertainity of yesterday's measurement. This confirms that we are aligned to a good spot, and there is no need to adjust the green QPD offsets.

Just for reference: when we run the ditherAlign TMSY script the maximum normalized PD1, PD4 values are 1.38(0.05), 1.09(0.05) respectively.  

Bubba is tied up with pulling a BSC door so I am posting a few photos for him.

Progress report on the DCS work:

Refrigeration piping continues, sheet metal work inside is almost done, and electrical work is well underway.

Covering for a sick operator in the morning and then Patrick will continue to help cover the rest of day. 

Here are notes from the morning thus far

H1LSC has RED DAQ bit

• Taking door off of BSC9 (Bubba, Kyle, Gerardo)
• Code restarted for Dust Monitors at EX (Jim B)
• 8:00 Yarm drift measurements 8-10am (Thomas
• 8:06  h0epics.cds.ligo-wa.caltech.edu:  "Virtual circuit disconnect"
• 8:19-8:50 EX Dust Monitor check (Jeff B)
• 8:28 Grouding plugs in SEI cans (Mitch/Hugh)
• 8:28 Betsy grabbing parts in LVEA and then heading into EX
• 8:30 HAM3 down for TFs for 8:30-930 (Jim)
• 8:45 Looking for IO 3IFO optics for Rodica
• 8:49 Electronic Test Stand decommissioning (pulling cables) Manny
• 8:55 Terminating LVEA cables for the morning (Aaron)
• 8:57 3IFO SUS storage Conainer work/no craning, some moving of boxes (Jeff B)

Rich, Jim, Seb, Fabrice

We can only see this noise line when the sensor correction is ON, so we have been chaising it in the the sensor correction channels, but could not find anything.

We are back to noise hunting in the ISI channels.

- The first plot attached shows  ASDs with sensor correction ON (2 nights ago). The amplitude of the peak is 2.5e-8 m/Hz^0.5

- The second plot shows ASDs with sensor correction OFF (last night).  The amplitude is 8e-9 m/Hz^0.5. No visible noise line...

We are getting the ISI local sensors data on HAM2 and HAM3 with the sensor correction OFF,  to perform signal subtraction, and see if the noise line could be burried in the seismic signal (and somehow amplified by the sensor correction?)

Evan, Alexa, Sheila

We went through the DRMI initial alignment today. We were able to run PRM_ALIGN fine. When we ran SRM_ALIGN we noticed that we were not feeding back to SR2 eventhough the asc wfs were designed to do so. This was something in guardian that was not properly updated. We fixed this problem, and also adjusted the guardian offloading script to clear history of the M1 locking filters since some of these now have integrators.

DRMI locked on 3f @ 12/06/2015 16:09:55 PST. We were able to engage all the ASC wfs loops except INP1, PRC1 which feedback to PRM. At this point we took transfer functions of each loop. We found that the PRCL UGF was low, and we had to increase the PRCL gain from 11 to 22. The MICH loop was comparable to previous measurement. Meanwhile the SRCL loop seemed to lose phase on the low frequency side of the phase bubble and be a bit flatter near the UGF. Comparing the times of the two SRCL transfer functions on conlog, it appears that the switch status for the SRCL filters has been changed. More invesitgation is required. We also noticed that the BS roll mode at 25 Hz had been rung up based on the DRMI spectrum, but not enough to disturb our lock.

After about 15 min we lost lock (most likely from an excitation). We could recover the lock; however, it only stayed locked when engaging the PR3 ASC wfs feedback this time; all other loops had to be turned off. DRMI was not staying locked for long periods of time, making it hard to take measurements. We took a BS oplev spectra and saw a peak at 19.6 Hz. The oplev damping has a large notch at 19.48 Hz. According to the SUS model awiki page it doesn't seem to correspond to a particular mode ... We are not totally sure if this is what is keeping us from locking.

Jim, Sebastien

We've been investigating a little more on the HAM3-ISI issue. Quick sum up: we see a 0.6Hz sharp peak on all DOFs when the Z sensor correction is on (see logs here and here).

First we checked the electronics. We swapped the STS input cables of the AA chassis between HAM2 and HAM3. This didn't do it, and the issue stayed on HAM3. This exclude the whole STS electronics chain except the AA chassis and ADC.

But, back in the December, the sensor correction was implement with a different seismometer (which means different AA chassis and different ADC), and the peak was already here. Thus we can say with confidence that it's not an electronics issue.

From there, couple of observations:

- The unity gain frequency of the nominal blend filter is 0.6Hz.

- When we switch from the nominal blend filter to a 750mHz blend, we don't see the peak anymore.

Given that, the nominal configuration of HAM3 is the same that the other ISIs, and the problem appears only on HAM3...

Also, by looking at the local transfer functions of HAM3, we see a lost of coherence around 0.6Hz (see files attached). Rubbing might explain the whole story... A soon as we have access to the platform, we'll do a driven transfer function in this bandwitdh and double check that hypothesis. In the meantime, we keep investigating on the blend configuration.

Expect to remove BSC9 West door in the morning for a brief incursion by others followed by door install and pump down.

WIth Rick's help, we have created a composite image of ETMy before, after, and before-minus-after using Matlab.  Due to saturation of the camera's photodetector in the 'after' photo (we believe due to higher power in the arm), the particles we removed during cleaning appear magenta.  Tomorrow, I hope to do the same with the IR photos. 

I repeated the measurement from alog 15783, just checking coherence between HAMs 2&3 after we changed HAM3 to look at the right seismometer. Nothing obvious, but I found something interesting. The FIR_IN signals should all be the exactly same at this point, and so should be 100% coherent, between the chambers. The Z signal is not, but the difference is only below 50 mhz, at around .6hz the coherence is almost 100% again. Attached plot shows measurement from the middle of last ni.

LVEA: Laser Hazard
Observation Bit: Commissioning  

07:30 Karen & Cris – Cleaning in the LVEA
09:05 Aaron & Filiberto – In LVEA cabling work at HAM3 & BS
09:25 Mitch – Working in LVEA West Bay cleanroom
09:43 Hugh – Working in LVEA West Bay area
09:44 Jim & Sebastien – In CER working on HAM2 Electronics
09:53 Andres & TJ – Working on 3IFO Quad storage modifications
10:25 Manny – Cable work around H2 electronics test stand
10:37 Filiberto & Aaron – Finished pulling cables at HAM3/BS. Started terminating these cables
10:50 Sheila – Transition End-X to laser safe  
11:36 Jim & Sebastien – Back in CER working on HAM2 Electronics
11:45 Mitch & Hugh – Out of the LVEA
12:48 Manny – Pulling cables around H2 electronics test stand
14:35 Kyle – End-X to prep for vent
15:16 Kyle – Going to End-Y 
15:28 Kyle – Going back to End-X

The attached plots are from the period when there were 4 people working in the PSL enclosure on Monday (01/05/15) between 09:00 and 13:00.    

Took DBB scans of the PSL this afternoon. Plots are posted below